1. Field of the Invention
This invention relates to a torque variation absorbing device for use in a driving axle system.
2. Description of the Related Art
A conventional torque variation absorbing device is disclosed in the Japanese Utility Model Laid Open No. 64-48448 published in 1989 without examination. In FIG. 2 the torque variation absorbing device comprises a drive plate 2 which is connected to a crank shaft 14 by a plurality of bolts 14a and a flywheel 3 including a surface 3a on which a clutch mechanism (not shown in the Figure) is mounted. The torque variation absorbing device comprises a plurality of damping mechanisms 12 disposed between the drive plate 2 and the flywheel 3, and each of the damping mechanisms 12 includes a torsion spring 13. The torque variation absorbing device comprises a driven plate 5 fixed to the flywheel 3 by a plurality of bolts 4, a hub 7 connected to the drive plate 2 by a plurality of screws 6 and a bearing 8 provided between the driven plate 5 and the hub 7. Furthermore the torque variation absorbing device possesses a friction member 9, a thrust plate 10 and a cone spring 11. An outer race 8a of the bearing 8 is pressed by the elastic force of the cone spring 11 in the direction of the clutch mechanism from the side of the crank shaft 14 through the driven plate 5.
When the clutch mechanism is released, a pressure plate (not shown in Figure) in the clutch mechanism is pressed in the direction from the right as seen in FIG. 2 and the surface 3a of the flywheel 3 receives the reaction force from the clutch mechanism. Therefore the flywheel 3 presses the cone spring 11 in the direction of the crank shaft 14 from the side of the clutch mechanism through the outer race 8a and the driven plate 5 against the elastic force of the cone spring 11. The flywheel 3 is moved a distance equaling the sum of a gap between a ball 8c and the outer race 8a and a gap between the ball 8c and the inner race 8b in the direction of the crank shaft 14 from the side of the clutch mechanism. Consequently the play of a clutch pedal increases upon the releasing of the clutch mechanism, and the initial stroke of the clutch pedal for releasing the clutch mechanism lengthens.